Anaplastic thyroid carcinoma: diagnostic challenges,histopathologic features and ancillary testing

Anaplastic thyroid carcinoma (ATC) is an aggressive thyroid malignancy with high mortality rate. This malignancy arises in thyroid follicular cells either denovo or with an associated differentiated thyroid carcinoma component. Clinically, it usually presents as a rapidly enlarging mass, pain and locally compressive symptoms. Histopathologic variability and heterogeneity often pose diagnostic challenges, especially in scant and paucicellular specimens. This article describes the clinical, histopathologic and molecular features of ATC and also addresses the associated diagnostic limitations and challenges.     

Molecular detection of Orientia tsutsugamushi strains circulating in Nagaland

The antigenic heterogeneity of Orientia in India is still unknown in many disease endemic areas. The present study aims to characterize the strains of O. tsutsugamushi circulating in Nagaland, Northeast India. Two patients clinically diagnosed with ST and hospitalized in Mon district hospital, Nagaland were identified from whom eschar tissues were collected. Both patients demonstrated antibodies against O. tsutsugamushi along with positive PCR amplification for 56 ?kDa gene. The prototype strain TA763 shared 90.4% homology with the sequences. Both the sequences formed a distinctive cluster demonstrating 100% similarity with strains identified from Thailand, Vietnam, China and southern parts of India.     

Post-keratoplasty corneal ulcers and bandage lenses

285 cases of penetrating keratoplasty in whom hydrophilic bandage lenses were fitted were analyzed for the occurrence of corneal ulcers. Of these eyes 26 developed culture-proven bacterial ulcers. No correlation could be made between any particular type of contact lens and the development of corneal ulcer. Although no single factor could be delineated which may be responsible for this problem, this risk appears to be escalated where host defense mechanisms are impaired. The clinician should recognize the potential risk in using bandage lenses when the cornea is immunosuppressed and completely denervated.     

Dynamic gadolinium-enhanced echo-planar MR imaging of the liver: Effect of pulse sequence and dose on enhancement

To develop guidelines for clinical magnetic resonance imaging of the liver, the authors undertook an animal study to investigate the effect of dose and pulse sequence on liver signal intensity in gadopentetate dimeglumine—enhanced echo-planar imaging. Serial imaging of the liver was performed in anesthetized rats after intravenous administration of five different doses (0.01, 0.05, 0.1, 0.2, and 0.5 mmol/kg) of contrast agent, with six different pulse sequences. The results show that gadopentetate dimeglumine—enhanced echo-planar images obtained during the perfusion phase can yield either positive (due to increased T1 relaxation rates) or negative (due to susceptibility-induced increased T2 relaxation rates) liver enhancement depending on choice of pulse sequence and dose. At the current clinically recommended dose of 0.1 mmol/kg, maximal liver signal enhancement was seen with a T1-weighted inversion-recovery sequence, while maximal liver signal diminution was seen with a T2*-weighted gradient-echo sequence. The authors conclude that gadopentetate dimeglumine—enhanced echo-planar imaging can provide T1, T2, and T2* contrast that may be exploited for both lesion detection and lesion characterization.     

Executive function impairments in children with attention-deficit hyperactivity disorder: do they differ between school and home environments?

OBJECTIVE: The primary purpose of this study was to compare parent and teacher reports of executive function (EF), as measured by the Behavior Rating Inventory of Executive Function (BRIEF), on a sample of children who had been diagnosed with attention-deficit hyperactivity disorder (ADHD). If differences were found, the secondary purpose was to explore these differences by determining which of the 8 BRIEF scales, each representing a different EF, would best predict symptoms of ADHD by the 2 proxy reporters. METHOD: We performed a secondary data analysis on the assessment information pertaining to 240 children, aged 5 to 15 years, accessing services at an urban Toronto psychiatric program specializing in ADHD. We compared parent and teacher ratings and applied logistical binary regressions to predict the probability of a child's meeting the criteria for clinically significant inattention and hyperactivity-impulsivity on the ADHD Rating Scale-IV. RESULTS: As expected, teachers reported more variety and severity of EF impairments than did parents. In addition, teachers used inhibition, organization of materials, and planning and organizing as predictors of ADHD symptoms, whereas parents relied predominantly on inhibition, working memory, and planning and organizing as the risk factors. CONCLUSION: Consistent with the current theory, EF impairments, particularly in inhibition, appear to underlie the behavioural manifestation of ADHD. However, parents and teachers do not always agree when reporting EF impairments at home and in school. Thus information from both types of informants is essential for understanding and treating children with this disorder.     

Psoriasis: To Cut or Not to Cut, What Say You?

BACKGROUND: A common problem facing patients suffering from psoriasis is the need for surgery that requires incision through active psoriatic skin. Many patients have been denied surgery because of the fear of an increased risk of infection, decreased wound healing ability, and worsening of the psoriatic lesions. OBJECTIVE: To assess the practices and beliefs of dermatologists and surgeons (orthopedic and plastic surgeons) faced with the decision of whether to operate through active psoriatic skin. METHODS: Dermatologists, orthopedic surgeons, and plastic surgeons selected from various professional membership lists from five representative cities were sent a survey to ascertain their opinions on operating on active psoriatic skin. Psoriatic patients were also given forms asking about the severity of their psoriasis and whether they had ever been denied surgery. RESULTS: Dermatologists are more likely to condone surgery in active psoriatic skin and to believe that there is not a risk of increased infection or decreased wound healing than are orthopedic surgeons and plastic surgeons. These findings are statistically significant (P<0.05). CONCLUSION: With proper preoperative measures and dermatologic treatment, surgery can be performed on active psoriatic skin in most cases with minimal reservations, although a controlled, prospective study is necessary to arrive at a definitive conclusion.     

Dynamic spin-echo MRI of liver cancer using Gadolinium-DTPA: animal investigation

An animal model of liver cancer was used to demonstrate that with a fast MRI technique, Gadolinium-DTPA increases tumor-liver contrast. A spin-echo pulse sequence with short repetition (TR) and echo-delay (TE) times (TR 250/TE 15/Excitations 1) has a scan time of 0.6 min, which allows early dynamic postcontrast infusion imaging. This is necessary to capture peak compartmental differences when an extracellular contrast agent such as Gadolinium-DTPA is used. This short TR/short TE pulse sequence also increases T1-dependent tissue contrast over the traditional (inversion recovery or spin echo) T1-weighted pulse sequences. Our studies suggest a significant potential for improved detection of liver metastases with Gadolinium-DTPA-enhanced liver MRI.     

Percutaneous obliteration of the cystic duct with a holmium:yttrium-aluminum-garnet laser: results of in vitro and animal experiments.

OBJECTIVE. The purpose of this study was to investigate the feasibility of using a holmium:yttrium-aluminum-garnet laser to permanently occlude the cystic duct in order to isolate the gallbladder from the biliary-enteric circulation and prevent gallstone formation. MATERIALS AND METHODS. To determine the optimal laser parameters (power and pulsing rate) for cystic duct thermocoagulation, 20 freshly excised porcine gallbladders with intact cystic ducts underwent low-energy (0.075-0.085 J/pulse) or high-energy (0.20-0.25 J/pulse) thermocoagulation. Histopathologic examination was done to determine the extent of cystic duct injury. After in vitro experiments, percutaneous transcholecystic laser thermocoagulation of the cystic duct was performed on 23 anesthetized domestic pigs (four controls). Cholangiograms immediately after laser thermocoagulation were obtained to assess cystic duct occlusion. Animals were sacrificed for histopathologic correlation immediately after laser thermocoagulation (n = 4), 72 hr later (n = 4), and 6 weeks later (n = 15). RESULTS. In the in vitro studies, all 10 cystic ducts in the high-energy group were occluded, while only four in the low-energy group were occluded. At histology, all cases in both groups showed circumferential injury to the cystic duct wall without injury to the cystic artery or vein. In the in vitro experiments, the cystic duct was successfully cannulated in 21 (91%) of 23 animals. Cholangiography after thermocoagulation showed occlusion of the cystic duct in 16 (84%) of 19 cases. Immediately after laser thermocoagulation, the cystic duct mucosa was circumferentially destroyed, whereas after 72 hr necrosis of the cystic duct wall and periductal tissues had occurred. By 6 weeks, all pigs had complete cystic duct fibrosis without injury to the common bile duct. CONCLUSION. Holmium:yttrium-aluminum-garnet laser thermocoagulation of the cystic duct can be performed easily, results in immediate cystic duct occlusion, and leads to permanent fibrous ductal obliteration by 6 weeks.